Summary: This Commentary highlights the distinction between biochemical and biological definitions of oxidative stress, discusses issues to consider when designing experiments to investigate oxidative stress, and proposes the ‘redox signalling hypothesis’ of life history.

Summary: Muscle can be a motor (work output) or a brake (work absorption), or can simply exert force; these functions and their costs are relevant to locomotion. This versatility is revealed by a varying stimulation pattern.

Summary: The intestinal hormone guanylin is shown to stimulate bicarbonate secretion into the lumen through NKCC2 inhibition and precipitate high Ca/Mg ions in seawater in the eel intestine, which enhances water absorption and promotes seawater adaptation.

Summary: The switch between diapause and direct development results in developmental pre-diapause plasticity in life history and metabolism but not in reserve accumulation in a seasonally polyphenic butterfly.

Summary: Alcids accelerate during both the upstroke and downstroke when swimming in shallow water, contrary to previous kinematic studies, but head stabilization limits the detectability of the true stroke–acceleration pattern.

Summary: Models for acid-base regulation by the goldfish kidney based on SIET measurements indicate a major role for proximal tubules in H+ secretion and HCO3− reabsorption, in contrast to HCO3− reabsorption and NH3/NH4+ secretion in distal and connecting tubules.

Summary: Increasing the magnitude of stretch results in a greater stretch–shortening cycle effect and an increased force at steady state following the stretch, probably because of the greater residual force enhancement.

Summary: Exposure to infochemicals from crushed conspecifics and heterospecifics alters embryonic developmental time, size and morphology of the first larval instar in a palaemonid shrimp, indicating that alarm cues are conserved in this taxon, providing embryos with an innate recognition of alarm cues.

Summary: Investigation of calcified tube growth of Serpulidae under low-pH conditions indicates that ocean acidification will negatively affect the initiation and persistence of both biofouling and epiphytic polychaete tube worms.

Other journals from The Company of Biologists

Editor-in-Chief Hans Hoppeler and Monitoring Editor Craig Franklin highlight new initiatives at JEB in response to the COVID-19 pandemic. To continue advancing knowledge in the field, we are encouraging proposals for meta-analysis papers and timely Reviews and Commentaries within the JEB remit. New grant categories analogous to the Travelling Fellowships will fund collaborative data projects and the development of online resources for early-career researchers. Read their Editorial to find out more.

In their Review, Hanane Hadj-Moussa and Ken Storey assess OxymiRs in over 20 animal species. They reveal a lack of universal microRNA strategy, showing that instead there are species-specific responses to oxygen deprivation.

Researchers at nine institutions in Ireland can now publish an unlimited number of Open Access articles in JEB, immediately and at no cost to them, following a three-year Read & Publish agreement between The Company of Biologists and IReL. Find out more and see the growing list of participating institutions.

We are expanding the Conversation series to focus on the experiences of researchers out in the field. We’ll go behind the scenes as researchers tell us about their experiences on trawlers, in deserts, up mountains and in the remotest regions of the poles. Find out more about the series in the Editorial.

In the first interview, JEB author and editor Craig Franklin talks about the risks and challenges of working in remote areas with animals in their natural environment.